The present invention relates to a cloth curtain lift controller for efficiently raising or lowering a cloth curtain.
1. Description of the Prior Art
Traditionally, a curtain is raised or lowered directly by a cord. Recently various designs for curtain lift controlling devices have been used. FIG. 1 illustrates a type of curtain lift controller according to the prior art, which is generally comprised of a cap A, a ring B, an axle C, a sliding wheel D, a stopper element E, a counter-stopper element G and a compression spring F. The compression spring F is set between the stopper element E and the counter-stopper element g; The stopper element E comprises a plurality of raised portions E1 respectively seated in the notches D1 of the sliding wheel D; The rod-like body C1 of the axle C is inserted through the sliding wheel D, the stopper element E and the compression spring F permitting its front semi-circular flange C11 to be secured in the semi-circular hole G1 of the counter element G; The ring B comprises a flange B1 set in a hole D3 on the base D2 of the sliding wheel D; a cap A comprises a side-wall portion A1 extending over pulley wheel portion D4 of the sliding wheel D. During operation, the sliding wheel D is rotated by a cord or chain through its toothed portion D5 so as to disconnect its notches D1 from the raised portions E1 of the stopper element E, the ribs D6 of the sliding wheel D are simultaneously driven to carry a curtain scroll to raise or lower a curtain. In operation, the notches D1 of the sliding wheel D must overcome the biasing force from the compression spring F before breaking away from the constraint of the raised portions E1. A disadvantage of this type of curtain lifting controller is that the raised portions E1 of the stopper element E and the compression spring may be easily damaged and affect the operation of the controller. Another disadvantage of this type of curtain lifting controller is that the notches D1 of the sliding wheel D may be easily disconnected from the raised portions E1 of the stopper element E when the connected curtain is directly pulled by an external force. Still another disadvantage of this type of curtain lifting controller is that with any damage to the raised portions E1 of the stopper element E, it will be impossible to stop the connected curtain at a desired position. All the above-said problems can be efficiently eliminated by means of the application of the present invention.